Question: What is the value of (2 + 3i)(2 - 3i)? (2019)
Options:
Correct Answer: 13
Exam Year: 2019
Solution:
Using the difference of squares: (a + b)(a - b) = a² - b². Here, (2)² - (3i)² = 4 - (-9) = 4 + 9 = 13.